Leopoldo Trieste

No comparison

2019 StudioCanal 4K Blu-ray (same as Optimum Blu-ray)

UK Second Sight 4K Blu-ray is FiM encoded and superior to French Severin or German 4K Blu-ray: see comparison

Germany Capelight Blu-ray > Criterion Blu-ray

Criterion has the original stereo

The Paramount 4K "restoration" is a desecration. It has completely revisionist color timing, harsh HDR, treatment of stock footage, bad encoding, selective DNR and grain management so bad that the entire screen frequently freezes up with only characters moving around in grain soup. It is so bad that the film's restorer Robert Harris publicly washed his hands of it saying essentially the 2007 restoration (with Willis and Coppola supervising) is how the film was intended and made. This is Paramount's modern version done their way. The new 1080p SDR Blu-rays in print are the crap 4K desecration master with the same problems still there just harder to spot and with crap encodes. Part II overall fares better than the first film but it has all the same problems. Randomly some shots are the worst in the trilogy looks mushy and manipulated to death.
The mono option is an unnecessarily processed version of the lossy mono from the 2008 Blu-ray. The 2008 Blu-ray of the 2007 Coppola Restoration while an imperfect outdated disc is LIGHT YEARS better than this 4K desecration. The only truly major issue is that it is very slightly redder than the 2007 finished master as seen on DCPs. The lossy mono on the 2008 Blu-ray is the best version of the original mix known to exist as it is better than the late 80's mastering for VHS and LaserDisc.
DFIC review of the hideous crap 4K Blu-rays: https://youtu.be/0uw6-Kcy_UA?si=ob1nDg0wTCvemjH0